The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 02, 2008
Filed:
Jul. 31, 2006
Sadanori Yamanaka, Tsukuba, JP;
Yoshihiko Tsuchida, Tsukuba, JP;
Yoshinobu Ono, Yawara-mura, JP;
Yasushi Iyechika, Matsudo, JP;
Sadanori Yamanaka, Tsukuba, JP;
Yoshihiko Tsuchida, Tsukuba, JP;
Yoshinobu Ono, Yawara-mura, JP;
Yasushi Iyechika, Matsudo, JP;
Sumitomo Chemical Company Limited, Osaka, JP;
Abstract
In order to improve light-emission efficiency without degrading protection performance of a light-emitting layer structure a three p-type layer structure composed of first to third layers is provided in contact with a light-emitting layer structure. The first layer is an n-type AlGaN layer that serves as a protective layer, the third layer is a GaN:Mg layer that serves as a contact layer and the second layer is an AlGaN:Mg layer formed between these layers as an intermediate layer. The provision of the intermediate layer enables an InGaN layer to be thoroughly protected from heat during growth of layers above even if the n-type AlGaN layer is made thin, whereby the GaN:Mg layer can be brought near the light-emitting layer structure to enhance the efficiency of hole injection into the light-emitting layer structure and thus increase the light-emission efficiency.